This project is a detailed study of the regulatory properties of malic enzyme and fumarase from the muscle tissue of Ascaris suum. We propose to study the effects of several normal metabolites on the Km, Vmax and normal saturation kinetics of the purified malic enzyme. These studies should quantitatively delineate the regulatory properties of the enzyme. Fumarase will be isolated and purified from the muscle of the parasite. This will be carried out by techniques developed in our laboratory. Purity will be ascertained by standard procedures. The effects of normal metabolites on fumarase activity will be tested to determine their specific influence on the enzyme. A tandem kinetic experiment using the malic enzyme and fumarase will be carried out and should yield information on the in vivo interactions of these enzymes and their regulators. Correlation of the results of the malic enzyme and fumarase experiments should allow the development of a theory on the control of the dismutation reaction in the parasite. The presence of regulatory mechanisms that control the rate of glycolytic flux by heterologous protein interactions will be ascertained by specific binding studies. Aldolase and glyceraldehyde 3-phosphate dehydrogenase will be adsorbed to the muscle protein F-actin. Stoichiometric binding studies coupled with kinetic and stability studies in the bound and unbound state should give information on the feasibility of in vivo regulation in this system.